346 ROBERT H. BOWEN. 



answer to this question may be postponed until the mechanism of 

 dictyokinesis has also been considered. 



Although the Golgi apparatus has been known for over twenty 

 years there is still scarcely a single adequate account of its exact 

 behavior in cell division. Duesberg's ('20) recent report of the 

 Golgi apparatus in the opossum and the account by Papanicolaou 

 and Stockard ('18) of the guinea pig, leave much to be desired 

 in the way of details, and it is difficult to draw any very trust- 

 worthy conclusions. It appears, however, that in these forms the 

 Golgi apparatus undergoes a simple fragmentation, the resultant 

 pieces being scattered throughout the cell and subsequently di- 

 vided in a way reminiscent of the chondriosome granules, for 

 example in the guinea pig. A similar distribution of previously 

 separate Golgi bodies has been described in Ascaris by Hirschler 

 ('13). Practically all other accounts agree in indicating a much 

 more complicated process. Plainer ('89) seems to have been the 

 first to study the division of the Golgi apparatus in detail. He 

 worked on the pulmonate Lima* material which has since been 

 extensively employed for the same purpose since its Golgi ap- 

 paratus seems especially resistant to acetic acid. Platner ob- 

 served the breaking up of the " Nebenkern " just prior to divi- 

 sion and the separation of the pieces into two groups which, 

 accompanying the centrioles, migrate to opposite sides of the 

 nucleus and when the spindle is formed become disposed more 

 or less radially around the centriole. At the second spermato- 

 cyte division, the same process is repeated. Platner also de- 

 scribed some interesting division phenomena of the individual 

 rods (dictyosomes?), which have not however been confirmed in 

 detail by later workers. The essential features to be noted in this 

 description are the fragmentation of the parts of the Golgi ap- 

 paratus and their distribution to the daughter cells seemingly 

 under the direct control of the centrioles. Since Platner's time 

 many others have examined the so-called " Nebenkern " of pul- 

 monates with most contradictory results, and it must be con- 

 fessed that none succeeded as well as did Platner in gaining a 

 complete conception of dictyokinesis. Of later workers, Murray 

 ('98) should be especially mentioned, for his observations on 

 Helix and Arion contain many details relative to the structure of 



